Deformation caused by the 2011 eastern Japan great earthquake monitored using the GPS single-epoch precise point positioning technique  

基于GPS单历元精密单点定位的2011东日本大地震形变特征研究(英文)

作　　者：郭金运[1,2] 原永东[1,2] 孔巧丽[1,2] 李国伟[1,2] 王方建[3] 

机构地区：[1]山东科技大学测绘学院,青岛266590 [2]海岛(礁)测绘技术国家测绘地理信息局重点实验室,青岛266590 [3]山东省地震局,济南250014

出　　处：《Applied Geophysics》2012年第4期483-493,497,共12页应用地球物理（英文版）

基　　金：supported partially by the National Natural Science Foundation of China(No.40974004 and 40974016);the Key Laboratory of Surveying and Mapping Technology on Island and Reef of NASMG,China(No.2011A01);the Key Laboratory of Advanced Surveying Engineering of NASMG,China(No.TJES1101)

摘　　要：Crustal deformation can provide constraints for studying earthquake rupture and shock wave transmission for the Mw9.0 eastern Japan great earthquake. Using the single- epoch precise point positioning （PPP） method and the appropriate positioning flow, we process GPS data from six IGS （International GNSS Service） sites （e.g., MIZU, TSK2, USUD, MTKA, AIRA and KSMV） located in Japan and obtain the positioning results with centimeter scale precision. The displacement time series of the six sites are analyzed using the least squares spectral analysis method to estimate deformations caused by the Mw9.0 mainshock and the Mw7.9 aftershock, and the cumulative displacements after 1 day. Mainshock displacements at station MIZU, the nearest site to the mainshock in the North （N）, East （E）, and Up （U） directions, are -1.202 m, 2.180 m and -0.104 m, respectively, and the cumulative deformations after 1 day are -1.117 m, 2.071 m and -0.072 m, respectively. The displacements at station KSMV, the nearest site to the Mw7.9 aftershock in the N, E and U directions, are -0.032 m, 0.742 m and -0.345 m, respectively. The other sites obviously experienced eastern movements and subsidence. The deformation vectors indicate that the horizontal displacements caused by the earthquake point to the epicenter and rupture. Elastic bounds evidently took place at all sites. The results indicate that the crustal movements and earthquake were part of a megathrust caused by the Pacific Plate sinking under the North American Plate to the northeast of Japan island arc.地壳形变信息为Mw9.0东日本大地震研究提供了地震破裂和地震波传播等研究的强制性约束。本文采用GPS单历元精密单点定位(PPP)技术,给出了单历元PPP的定位流程,对日本的6个IGS站(MIZU、TSK2、USUD、MTKA、AIRA、KSMV)的30s采样率观测数据进行了处理,获得了厘米级单历元定位精度。采用最小二乘谱分析方法,分析了6个IGS站的位移时间序列,解算了Mw9.0主震和Mw7.9余震造成的影响以及大地震当天的累计形变。距离震中最近的MIZU站在主震发生后在N、E和U方向上分别产生了-1.202m、2.180m和-0.104m位移,在N、E和U方向的单天累计形变量分别为-1.117m、2.071m和-0.072m。距离Mw7.9余震最近的KSMV站在N、E和U方向的单天累计形变量分别为-0.032m、0.742m和-0.345m。其他站点都有明显的向东运动和下沉。地震造成的地面位移都指向震中,并且台站位移存在明显的弹性回跳。这也说明日本岛弧东北部地区的地壳运动和地震活动是沉入北美板块之下的太平洋板块反作用造成的逆冲过程。

关 键 词：Eastern Japan great earthquake GPS single-epoch precise point positioning crustal deformation 

分 类 号：P228.4[天文地球—大地测量学与测量工程]